Tiffani Thiessen/Kelly Kapowski

Tiffani-Amber Thiessen (she later dropped the Amber) played the popular cheerleader at Bayside and Zach's on-again-off-again girlfriend. Diamond claims in his book that the on-screen couple carried on a romance in real life as well.
When the series ended, Thiessen moved to a more seductive zip code, "90210," to play the manipulative vixen Valerie Malone. Thiessen and co-star Brian Austin Green began a seven-year romance before Thiessen left the series in 1998. Green married another bright-eyed brunette beauty, Megan Fox.
In addition to a memorable role as Honey DeLune opposite Tim Meadows in 2000's "The Ladies Man," Thiessen played Billie on the short-lived series "Fastlane." Her most recent role on "What About Brian" was cut short when the series was canceled. Now 39, Thiessen stars in the hit series "White Collar" and has a 2-year-old daughter, Harper Renn, with husband actor Brady Smith.
She recently posed in her shirt and underwear for website Me in My Place, telling ABC News about her two decades as a sex symbol, "I think the older you get, it feels good that you can still do that little bit."